Edward



E. 0. BAKER.

WRITING INSTRUMENT.

APPLICATION FILED MM. 3'. 1919 Patented Oct. 21, 1919.

gamma 14mm wwwaooeo vided with a cap that normall UNITED STATES PATENT OFFICE.

EDWARD O. BAKER, OF SHANGHAI, CHINA.

WRITING INSTRUMENT.

Specification of Letters Patent.

Patented Oct. 21, 1919.

Application filed March 3, 1919. Serial No. 280,207.

produce a writing instrument in which a.

compressed air containing chamber communicates with the ink containing chamber, a stem having a point on the outer end thereof bein arranged in the ink chamber and controlling the outlet passage of the nk chamber as well as the port of communication between the ink chamber and the air chamber, the said stem being spring influenced and the point thereof, when brought to writing position will, bya pressure of the operator on the barrel in a downward direction upon the outlet for the ink chamber uncover the port between the air chamber and the ink chamber, the degree of pressure between the barrel and point determining the quantity of the outfiowing ink, and consequently providing for the writing or marking of light and heavy or shaded char acters.

It is a further object of the invention .to produce a writing instrument including an ink containing chamber and an air chamber co-extensive therewith, thewriting point of the instrument controlling the outlet of both of said chambers, and the device being procovers the point of the instrument, but wh1ch when arranged upon the opposite end thereof and subject to a reciprocatory movement will fill and compress air in the air chamber.

A still further object of the invention is to produce an inking instrument which shall be of a comparatively simple construction cheaply manufactured, having means for insuring the non-leakage thereof, and also having means for ejecting the mk'by air pressure so as to insure a steady flow of ink and at the same time the non-clogging of the device.

The foregoing objects, and others which will appear as the nature of the invention is better understood, may be accomplished by a simple construction, combination and operative arrangement of parts, such as is illustrated by the accompanying drawings.

In the drawings:

The figure illustrates an approximately central longitudinal section through the improvement, the dotted lines indicating the arrangementof the cap when the same is not employed as a pump for forcing air into the air chamber, or when the instrument is notin use.

The improvement contemplates the employment of a barrel 5 having interior threads 7 from the outer end 6 thereof. The threads 7 are engaged by the threaded end of a hollow frusto-conical member comprising 0 a nozzle 8.

The barrel 5 is approximately centrally provided with an interior partition 9 dividing the barrel into an ink chamber 10, disposed opposite and communicating with the nozzle 8, and a compressed air chamber 11. The outer end of the barrel 5 is closed, but is provided with an opening that is normally closed by an inwardly opening valve 12. The partition 9 is also rovided with an opening and the ink cham' er 10, outward of the said partition 9 has secured therein one or a plurality of transverse members in the nature of brackets 13. These" brackets are provided with openings for a longitudinally movable controlling stem 14. The stem has its outer end cone-shaped as at 15, the said end being arranged in the mouth of the nozzle 8, and projecting slightly outward of said mouth. The inner end of the stem 14 is preferably provided with a plug 16 that forms a valve for the opening in the partition 9. In this respect it is to be stated that valve may control t e opening in the partition, such valve being operated by an in ward movement of the controllin stem 14, when the device is brought to writing position.

The cap for the barrel is indicatedvby the numeral 17 and has its closed end provided with an opening controlled by an inwardly opening valve 18. The cap 17, at the mouth thereof has seated therein a compressible gasket 19 which engages with the outer surface of the barrel 5. It will be apparent that when the cap 17 is arran ed upon the barrel, as illustrated by the ull lines in the figure of the drawing, a reciproeatory movement imparted thereto will force air through the openin in the air chamber 11, and compress suc air in the said chamber.

Exerting a tension between one of the brackets 13 and the controlling stem 14 is a helical spring 20. This spring normally forces the controlling stem outwardly, bringing the cone-shaped writing point 15 in tlght frictional engagement with the mouth of the nozz1e8, and likewise causing the plug 16 to close the opening or port in the partition, or to bring the said stem out of contact with the valve which may be employed for controllin the said port.

The ink chamber is fil ed by removing the nozzle. Air is compressed in the air chamber as previously described. When brought to writing position a pressure is necessarily exerted on the point 15, causing the member 1a to be moved inwardly against the tension or pressure of the spring 20, opening the air chamber. The air entering the ink chamber forces the ink at an even flow over the controlling stem onto the writing point 15. The greater the pressure upon the point 15 the greater the flow thereon, and consequently the device may be successfully employed for fine or heavy writing. When the device is not in use the opening the nozzle and likewise ink chamber.

2. In a writing instrument, an ink chamber, an air chamber COll'lll'llll'llUtltll'lg therewith, said air chamber having an outer valve cont-rolled port, a valved member arranged for reciprocation on the air chamber designed to deliver air thereto and to compress air therein, a writing stem controlling the port between the air and ink chamber and the outlet of. the ink chamber and designed, when pressure is exerted thereon to open the outlet of the ink chamber and v the port between the air and ink chambers.

3. In a central feed writing instrument, a barrel divided into a communicating ink chamber and air chamber, a conical nozzle removably connected with the ink chamber, a valved port at the closed end of the air chamber, a spring influenced stem having a conical writing point controlling the outlet of the nozzle and the port of communication between the air and ink chambers and designed, when pressure is exerted against the point thereof to open the nozzle and the said port, and a cap having its closed end provided with a valve for the barrel, as and for the purpose set forth.

In testimony whereof I aflix my signature.

EDWARD O. BAKER. 

